1. Field of the invention
This invention relates, in general, to rotary compressors laterally installed in an apparatus, such as, e.g., air conditioners, refrigerators, etc., for compressing refrigerant in the refrigerating circuit of the apparatus. In particular, the invention relates to a rotary compressor provided with a lubricating oil pump mechanism for automatically feeding a lubricating oil to bearings of the compressor.
2. Description of the prior art
One example of a conventional rotary type compressor is disclosed in U.S. Pat. No. 4,557,677 issued to the same assignee as the present invention, and entitled VALVELESS LUBRICANT PUMP FOR A LATERAL ROTARY COMPRESSOR. FIG. 1 shows the prior art rotary compressor. A compressor 11 disposed in a hermetic container 13 typically includes a motor section 15 and a compressing section 17. Since compressor 11 is horizontally installed in an apparatus (not shown), motor section 15 is arranged on one side, and compressing section 17 is arranged on the other side of container 13 in the lateral direction.
Motor section 15 includes an annular stator 15a and a rotor 15b rotatably positioned inside stator 15a. Rotor 15b is provided with a lateral rotation shaft 16 for driving compressing section 17. Compressing section 17 is provided with a pair of bearings 19 and 21 for rotatably supporting lateral rotation shaft 16, and a cylinder 23 arranged therebetween. A compressing chamber 25 is established by the pair of bearings 19 and 21 and cylinder 23. Compressing chamber 25 is provided with a roller 27, which is secured to an eccentric portion 16a of rotation shaft 16. Therefore, roller 27 eccentrically rotates in compressing chamber 25 in response to the rotation of shaft 16. Cylinder 23 is provided with a blade 29, which is forcibly urged toward roller 27 by a spring 31 to reciprocate in the radius direction of compressing chamber 25. Blade 29 partitions compressing chamber 25 into a high pressure cell and a low pressure cell for compressing a gas fluid, e.g., refrigerant gas, fed to compressing chamber 25 through an intake pipe 33, shown in FIG. 2, in response to the eccentric rotation of shaft 16.
As shown in FIG. 1, an ordinarilly known oil pump mechanism 35 is provided in compressing section 17 for automatically feeding the lubricating oil stored in a bottom portion of container 13 to bearings 19 and 21 of compressing section 17 in response to the reciprocal movement of blade 29. The oil pump mechanism 35 includes a blade chamber 37 in the bottom portion of container 13. Blade chamber 37 is defined by cylinder 23 and each portion 39a, 39b individually extending from the pair of bearings 19 and 21. One end of an oil supply pipe 41 is in fluid communication with blade chamber 37, and the other end thereof is fluidly connected to an oil supply hole 43 of rotation shaft 16. A lubricating oil drawing hole 45 is provided on the lower portion of oil supply pipe 41 facing the bottom of container 13. Blade 29 reciprocates into blade chamber 37. In response to the reciprocal movement of blade 29, the lubricating oil in container 13 is periodically fed to bearings 19 and 21 through lubricating oil drawing hole 45, blade chamber 37 and oil supply pipe 41. In particular, when blade 29 moves toward rotation shaft 16, the lubricating oil in container 13 is drawn into blade chamber 37 through lubricating oil drawing hole 45 of oil supply pipe 41. When blade 29 moves in the centrifugal direction, the lubricating oil in blade chamber 37 is fed to oil supply hole 43 through oil supply pipe 41.
However, in the above-described prior art compressor, since blade chamber 37 is located at the bottom portion of container 13, the intake port (not shown) of compressing section 17 for drawing refrigerant has to be located essentially at the bottom portion of container 13. As a result, the installation height of the compressor assembly increases, as shown in FIG. 2, when intake pipe 33 from an accumulator 47 is connected to the intake port of the compressor. Furthermore, since a long intake pipe 33 is needed when accumulator 47 is attached to the side surface of container 13, such a long intake pipe may hinder the installation of environmental devices, such as a fan device, or other electrical component, close to the compressor, and may easily contact the environmental devices. The lubricating oil stored in container 13 maintains a prescribed level. Blade chamber 37 is disposed in a base portion 48. The relatively large volume of base portion 48 which is dipped in the lubricating oil causes a shortage of lubricating oil to the compressor.